Argon Elemental Symbol
Argon



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Argon Argon Argo Argônio Argón Argon

Argon Bohr ModelArgon is a Block P, Group 18, Period 3 element. The number of electrons in each of Argon's shells is 2, 8, 8 and its electronic configuration is [Ne] 3s2 3p6. In its elemental form argon's CAS number is 7440-37-1. The argon atom has a covalent radius of 106±10.pm and it's Van der Waals radius is 188.pm. Air is the primary raw material used to produce argon products. Argon constitutes 1.28% by mass and 0.934% by volume of the Earth's atmosphere. Argon was discovered and first isolated by Lord Raleigh and Sir William Ramsay in 1894. Argon was the first noble gas to be discovered.

Argon is non-toxic. Argon information, including technical data, safety data and its high purity properties, research, applications and other useful facts are specified below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity and thermal properties are included.


  • Properties
  • Safety Data
  • Research
  • Isotopes
  • Other Elements

Argon Properties


GENERAL PROPERTIES   PHYSICAL PROPERTIES  
Symbol: Ar Melting Point: -189.36 oC, -308.848 oF, 83.79 K
Atomic Number: 18 Boiling Point: -185.85 oC, -302.53 oF, 87.3 K
Atomic Weight: 39.95 Density: 1656 (40 K) kg m-3
Element Category: noble gases Liquid Density @ Melting Point: 1.40 g·cm−3
Group, Period, Block: 18, 3, p Specific Heat: N/A
    Heat of Vaporization 6.53 kJ mol-1
CHEMICAL STRUCTURE Heat of Fusion 1.21 kJ mol-1
Electrons: 18 Thermal Conductivity: 17.72x10-3  W·m−1·K−1
Protons: 18 Thermal Expansion: N/A
Neutrons: 22 Electrical Resistivity: N/A
Electron Configuration: [Ne]3s23p6 Electronegativity: N/A
Atomic Radius: N/A Tensile Strength: N/A
Covalent Radius: 106±10 pm Molar Heat Capacity: 5R/2 = 20.786 (Cp) J·mol−1·K−1
Van der Waals radius: 188 pm Young's Modulus: N/A
Oxidation States: 0 Shear Modulus: N/A
Phase: Gas Bulk Modulus: N/A
Crystal Structure: face-centered cubic Poisson Ratio: N/A
Magnetic Ordering: diamagnetic Mohs Hardness: N/A
1st Ionization Energy: 1520.58 kJ mol-1 Vickers Hardness: N/A
2nd Ionization Energy: 2665.88 kJ mol-1 Brinell Hardness: N/A
3rd Ionization Energy: 3930.84 kJ mol-1 Speed of Sound: (gas, 27 °C) 323 m·s−1
       
IDENTIFIERS   MISCELLANEOUS  
CAS Number: 7440-37-1 Abundance in typical human body, by weight: N/A
ChemSpider ID: 22407 Abundance in typical human body, by atom: N/A
PubChem CID: 23968 Abundance in universe, by weight: 200000 ppb
MDL Number: MFCD00003431 Abundance in universe, by atom: 6000 ppb
EC Number: 231-147-0 Discovered By: Lord Rayleigh and William Ramsay
Beilstein Number: N/A Discovery Date: 1894
SMILES Identifier: [Ar]  
InChI Identifier: InChI=1S/Ar Other Names: Argo, Argônio
InChI Key: XKRFYHLGVUSROY-UHFFFAOYSA-N  
       
       
       
       
       


Recent Research & Development for Argon

  • Argon cluster ion source evaluation on lipid standards and rat brain tissue samples. Bich C, Havelund R, Moellers R, Touboul D, Kollmer F, Niehuis E, Gilmore IS, Brunelle A. Anal Chem. 2013 Jul 22. [Epub ahead of print]
  • Plasma of argon accelerates murine fibroblast adhesion in early stages of titanium disk colonization. Canullo L, Cassinelli C, Götz W, Tarnow D. Int J Oral Maxillofac Implants. 2013 Jul-Aug;28(4):957-62. doi: 10.11607/jomi.2664.
  • Neuroprotection against Traumatic Brain Injury by Xenon, but Not Argon, Is Mediated by Inhibition at the N-Methyl-D-Aspartate Receptor Glycine Site. Harris K, Armstrong SP, Campos-Pires R, Kiru L, Franks NP, Dickinson R. Anesthesiology. 2013 Jul 17. [Epub ahead of print]
  • Endoscopic lung abscess drainage with argon plasma coagulation. Goudie E, Kazakov J, Poirier C, Liberman M. J Thorac Cardiovasc Surg. 2013 Jul 13. doi:pii: S0022-5223(13)00596-5. 10.1016/j.jtcvs.2013.05.031. [Epub ahead of print] No abstract available.
  • A Randomized Clinical Trial of Selective Laser Trabeculoplasty Versus Argon Laser Trabeculoplasty in Patients With Pseudoexfoliation. Kent SS, Hutnik CM, Birt CM, Damji KF, Harasymowycz P, Si F, Hodge W, Pan I, Crichton A. J Glaucoma. 2013 Jul 17. [Epub ahead of print]
  • Thorium Fluorides ThF, ThF2, ThF3, ThF4, ThF3(F2), and ThF5(-) Characterized by Infrared Spectra in Solid Argon and Electronic Structure and Vibrational Frequency Calculations. Andrews L, Thanthiriwatte KS, Wang X, Dixon DA. Inorg Chem. 2013 Jul 15;52(14):8228-33. doi: 10.1021/ic401107w. Epub 2013 Jun 27.
  • Argon Beam Coagulation versus Fibrin Sealant for Hemostasis Following Liver Resection: A Randomized Study in a Porcine Model. Katkhouda N, Friedlander M, Darehzereshki A, Mason RJ, Zehetner J, Moazzez A, Chan LS, Kiyabu M, Kirkman E, Kirkman P, Ravari F, Degnera E, Drangsholt S, Khalaf1 N. Hepatogastroenterology. 2013 Jun 27;60(125):1110-1116. doi: 10.5754/hge11707.
  • Matrix Infrared Spectra and Density Functional Calculations for New Iso-Halomethanes: CHCl2-Cl, CHFCl-Cl, CFCl2-Cl, CHBr2-Br and CBr3-Br in Solid Argon. Cho HG, Andrews L. J Phys Chem A. 2013 Jun 26. [Epub ahead of print]
  • Feasibility and efficacy of argon plasma coagulation for early esophageal squamous cell neoplasia. Min BH, Kim ER, Lee JH, Kang KJ, Rhee PL, Kim JJ, Rhee JC. Endoscopy. 2013 Jul;45(7):575-8. doi: 10.1055/s-0033-1344025. Epub 2013 Jun 25.
  • Common versus noble- Bacillus subtilis differentially responds to air and argon gas plasma. Winter T, Bernhardt J, Winter J, Mäder U, Schlüter R, Weltmann KD, Hecker M, Kusch H. Proteomics. 2013 Jun 21. doi: 10.1002/pmic.201200343. [Epub ahead of print]
  • Transition from ripples to faceted structures under low-energy argon ion bombardment of silicon: understanding the role of shadowing and sputtering. Basu T, Datta DP, Som T. Nanoscale Res Lett. 2013 Jun 19;8(1):289. doi: 10.1186/1556-276X-8-289.
  • Meta-analysis of selective laser trabeculoplasty with argon laser trabeculoplasty in the treatment of open-angle glaucoma. Wang H, Cheng JW, Wei RL, Cai JP, Li Y, Ma XY. Can J Ophthalmol. 2013 Jun;48(3):186-92. doi: 10.1016/j.jcjo.2013.01.001.
  • [Electrocautery Snare Is Combined with CO2 Cryosurgery and Argon Plasma Coagulation for the Treatment of Airway Tumors and Granulomas]. Wang H, Li D, Zhang N, Zou H, Zhang J, Li J, Liang S. Zhongguo Fei Ai Za Zhi. 2013 Jun 20;16(6):294-8. doi: 10.3779/j.issn.1009-3419.2013.06.04. Chinese.
  • C-Cl Activation by Group IV Metal Oxides in Solid Argon Matrixes: Matrix Isolation Infrared Spectroscopy and Theoretical Investigations of the Reactions of MOx (M = Ti, Zr; x = 1, 2) with CH3Cl. Zhao Y. J Phys Chem A. 2013 Jul 11;117(27):5664-74. doi: 10.1021/jp4032095. Epub 2013 Jul 1.
  • On the hysteresis of argon adsorption in a uniform closed end slit pore. Fan C, Do DD, Nicholson D. J Colloid Interface Sci. 2013 Sep 1;405:201-10. doi: 10.1016/j.jcis.2013.04.052. Epub 2013 May 21.
  • Argon isotopic composition of Archaean atmosphere probes early Earth geodynamics. Pujol M, Marty B, Burgess R, Turner G, Philippot P. Nature. 2013 Jun 6;498(7452):87-90. doi: 10.1038/nature12152.
  • Study of the effect of post-packaging pasteurization and argon modified atmosphere packaging on the sensory quality and growth of endogenous microflora of a sliced cooked meat product. Pérez-Rodríguez F, Zamorano AR, Posada-Izquierdo GD, García-Gimeno RM. Food Sci Technol Int. 2013 Jun 3. [Epub ahead of print]
  • Argon-Induced Pressure Broadening, Shifting, and Narrowing in the CN A2?-X2S+ (1-0) Band. Forthomme D, McRaven CP, Sears TJ, Hall GE. J Phys Chem A. 2013 Jun 11. [Epub ahead of print]
  • Peptide dissociation patterns in secondary ion mass spectrometry under large argon cluster ion bombardment. Gnaser H, Fujii M, Nakagawa S, Seki T, Aoki T, Matsuo J. Rapid Commun Mass Spectrom. 2013 Jul 15;27(13):1490-6. doi: 10.1002/rcm.6599.
  • Controlled argon beam-induced desulfurization of monolayer molybdenum disulfide. Ma Q, Odenthal PM, Mann J, Le D, Wang CS, Zhu Y, Chen T, Sun D, Yamaguchi K, Tran T, Wurch M, McKinley JL, Wyrick J, Magnone K, Heinz TF, Rahman TS, Kawakami R, Bartels L. J Phys Condens Matter. 2013 Jun 26;25(25):252201. doi: 10.1088/0953-8984/25/25/252201. Epub 2013 May 24.

Argon Isotopes


Argon has three stable isotopes: 36Ar, 38Ar, and 40Ar.

Nuclide Symbol Isotopic Mass Half-Life Nuclear Spin
36Ar 35.967545106 Observationally Stable 0+
38Ar 37.9627324 Stable 0+
40Ar 39.9623831225 Stable 0+